Steam-pump or air-compressor.



K. DOUGAN. sEAM PUMP 0R Am COMPRESSOR.

APPLICATION FILED IAN. I6. 1909. @www v A 9 I E Qa mS EN NGN@ PatentedMay 16, 1916..

marre -f KENNEDY DOUGAN, OF MINNEAPOLIS, MINNESOTA.

STEAM-PUMP OR AIR-COMPRESSOR.

Specification of Letters Patent.

Patented liiay 16, 1916.

Application filed january 16, 1909. i Serial No. 472,668.

To all 'whom t may concern Be it known that I, KENNEDY DOUGAN, a citizenof the United States, and resident of Minneapolis, in the county ofHennepin and State of Minnesota, have invented certain new and usefulImprovements in Steam-Pumps or Air-Compressors; and I do hereby declarethe following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

The object of this invention is to provide a direct acting steam pump orair compressor in which steam may be expanded in such a manner that theeiiciency will be equal to that of the best type of flywheel steam pumpor air compressor.'

A further object is to provide a direct acting pump or air compressorthat will oc-` cupy small floor space, and be of comparatively cheapconstruction, and as compared with other direct acting pumps, willoperate without jar or shock.

In the machine herein disclosed, the pistons start gradually, acquirevelocity, and come to rest gradually.

In common pumps without fly-wheels the pistons are moving at fullspeedto the end of their stroke, which requires them to be checked suddenly,causing undesirable viA brations. In the invention herein disclosed,steam is admitted to the steam cylinder at boiler pressure andautomatically cut off atthe required point to carry the piston'to theend of its stroke. At the beginning of said stroke and up to the pointin the stroke where the entire steam pressure on the piston falls, untilit only equals the entire re.

sisting pressure on the water or air piston,

the excess 'of energy in the steam end is eX- pended in giving velocityto a heavyweight, connected to the piston rod. The energy thus stored isgiven out in useful effect in nishing the stroke.

In the accompanying drawings-Figure' 1 is a vertical longitudinalsection of a direct acting steam pump, disclosing the es-4 sentialfeature of the invention, a part of the water end being broken away;Fig. 2 isv a vertical cross-section, on a reduced scale, taken on linea-b of Fig. 1.

1 designates, as a whole, the steam cylinder, having the admission ports2 and 3, and the exhaust ports 4 and 5. Preferably, two 55 separate andindependent admission valves are employed, being steam-actuated andhaving respective pilot valves in housings 6 and 7.

8 and 9 indicate projections on the stems 60 of the pilot valves,adapted to be engaged by valve operating devices 50 and 51.

Before completing a description of the steam apparatus, the salientfeature of the construction will be described. This -consists of a heavyweight, 10*12, secured to the piston rod 13 but supported in such a waythat no part of its weight is borne by said rod. As shown, the weight isprovided with a roller 14 that rests upon a track '70 beam 15, the endsof which are supported by the cylinders of the pump, or in 'anypreferred way. The piston rod 13 passes through the center' of theweight 10-12, which is shown as cast in two parts, 10 and 75 12 one ofwhich is laterally removable. Said parts are secured together by `bolts16. The entire weight' may be installed or removed without disturbingthe piston rod. Said rod may be enlarged, as shown at 13', and 80 thebore of the weight correspondingly enlarged, to prevent any slippage ofthe weight upon the rod. The cylinder 17 may be that of anyreciprocating pump or air compressor. 'Ihe valve-operating members S5 50and 51 may conveniently be mounted on rods 18, 19, secured toprojections on or of the weight 10-12. rfhe device 50 is pivoted to asleeve 52 and the device 51 is pivoted to a sleeve 53 slidable on therod 19, said 90 sleeves being adjustably connected by a lazy-tongconstruction 5a and held in iXed position'by an arm 55 held by means ofa sleeve 56 and set screw 57 fast upon rod 18.

Means should be provided within the steam cylinder for cushioning thepiston. I have devised and shown herein, certain means for providingsteam cushionsfor the piston'without involving any added clearanceduring normal operation. The normal stroke of the piston is between theinner ends of ythe ports 2 and 3.

24 and 25 are inner, yieldable cylinder heads, whose inner faces lieclose to the pis- A if?? ton faces at the ends of the stroke. Thechambers 2G, 27 behind said heads may be closed air tight, but it isdeemed better to connect said chambers with the steam supply so thatsteam at boiler pressure will at all times fill them. rlhe pipes 28 and29 have this function, being connected to the steam-chest 30. Chambers26, 27 are provided with drain-cocks 81, 32 for water of condensation.

As the piston rod 13 must pass through one of the inner heads, 2l, 25,the construction shown is recommended as providing accessible packingsfor the piston rod. Head 25 is formed with a sleeve 33, threaded on itsouter end to receive an internally threaded stuffing-box 3i. The sleevepasses slidably through the fixed cylinder head, which is provided witha gland 35.

Normally, that is when relativ-e steam and water pressures arc normal,the inner heads will be moved but slightly or not at all, at the ends ofthe piston strokes. When, however, a relative steam pressure increasesor the relative water pressure decreases, the piston may be carriedfarther, in which case it cannot strike the head 2% or 25 but willhighly compress the steam between them and will force the head 2-l or 25to yield.

The initial movement of the piston will cut off the port to which thepipe 28 or 29 is connected, and the steam being thereby conned in thenarrow space between the lixed and movable cylinder heads will offergreat resistance to continued motion of the piston. ln addition,exterior buffers may be provided, for example as shown in the drawing.Heads 20 are carried by heavy rods 21 secured to the weight 10-12.Cooperative cylinders 22 are secured to, or cast integral with, thecylinders 1 and 17. The lengths of the rods 21 are such that when thepiston stroke does not exceed normal length, the heads 2O will onlyslightly enter the cylinders, not sufliciently to cause compression kofair therein. The compression will occur whenever the pistons are driventoo far either way. rlhus the exterior buffers coact with the interiordevices before described, and relieve the cylinder heads of a part ofthe stress set up by compression of steam.

The invention is not limit-ed to a weight secured directly to the pistonrod. The use of a weight in vertical pumps in which the piston is raisedby steam and driven down by a weight, is set forth in a separateapplication for Letters Patent filed January 16th 1909 and bearingSerial No. 473,669.

On the steam cylinder any suitable valve gear may be employed. Nospecial valve gear is shown, as this invention does not relate to thatportion of the mechanism. The cutoff isto be so adjusted that thepistons will be driven to the ends of their stroke by the combinedforces of steam pressure and momentum -of the moving parts.`

The operation of the pump will be fully understood from what has beensaid hereinbefore.

I claim:

1. A direct acting steam pump comprising two cylinders, pistons therein,a track above the cylinders bridging the space between the cylinders, aninertia weight between the cylinders, an arm on the weight extendingabove the track, an anti-friction roller on the arm and resting upon thetrack thereby suspending a'nd supporting the weight, a piston rodconnecting the pistons and extending through the weight, and meansconnecting the rod to the weight to move the same therewith.

2. A direct acting steam pump, comprising cylinders, pistons therein, apiston rod connecting the pistons, an inertia weight connected to andactuated by said rod, means other than said rod for supporting saidweight, buffers exterior to the cylinders of the pump, and means carriedby the weight coperating therewith to check the excess movement of theweight.

8. A direct acting steam pump or air compressor, comprising steam andpumping cylinders having their pistons connected by a common piston rod,an inertia weight connected to the rod to be moved thereby, buffermembers secured to. said weight, and co-acting buffer members fixed inposition to co-act with said members on the weight to check said weightwhen the piston stroke exceeds the normal.

4. A direct acting steam pump comprising steam and pumping cylindershaving their pistons connected by a common piston rod, an inertiaweightconnected to said rod for movement therewith, air-cushion members fixedin position adjacent the cylinders, and co-acting piston heads carriedon the weight in alinement with said aircushion members and positionedrelatively thereto so that when the piston stroke exceeds the normallength, said members will operate to check the movement of the weight. j

5. A steam pump comprising steam and pumping cylinders having theirpistons connected by a common piston rod, an inertia weight connected toand actuated by the piston rod, movable cylinder heads in the steamcylinder spaced from the fixed cylinder heads, steam connectionsentering said spaces between the fixed and movable 'cylinder heads atpoints just at the limit of the movable heads so that the initialmovement thereof Will cut off the steam from he spaces between the fixedand yieldable ieads.

6. A steam pump comprising steam and pumping cylinders having theirpistons connected by a common piston rod, an inertia weightindependently supported for reciprocation between the cylinders andconnectand movable heads at a point just inside of the edge of themovable cylinder head when the same is in its normal or most inwardposition, so that the initial movement of the yielding heads will cut 0Ethe steam from the spaces.

7. A steam pump comprising steam and pumping cylinders having theirpistons connected by a common rod, an inertia weight supported forindependent reciprocation between the cylinders and connected with thepiston rod for movement thereby, buffer members secured to the weight,coeacting fixed buifer members adjacent the cylinders to retard theweight when it exceeds its normal movement, movable cylinder headswithin the steam cylinder spaced from the ends thereof, and steamconnections entering the spaces between the movable and iiXed cylinderheads at a point just inside of the edge of the movable heads when intheir normal or most inward position, so that the initial movement ofthe head will cut off the steam and check movement of the piston throughcompression of the steam in the said 3 5 spaces.

8. A steam pump comprising cylinders, pistons therein, a piston rodconnecting the pistons, an inertia weight connected to and actuated bythe piston rod, a steam cylinder having in the ends thereof inneryieldable cylinder heads, the piston rod passing through one of saidheads, said head being formed with a sleeve passing through a bore inthe iiXed cylinder head, packing between said sleeve and the liXedcylinder head, and packing between the piston rod and said sleeve.

9. A steam pump, comprising two cylinders in a horizontal alinement,pistons therein, a piston rod connecting the pistons, an inertia weightintermediate the pistons and through which the piston rod passes, atrack for supporting the weight, buffer members secured to the weight,co-acting buffer members iXed in position to co-act with said buffermembers when the piston exceeds its normal stroke, yielding cylinderheads within the steam cylinder with spaces between the yielding heads,and the lined heads and steam connections to said spaces, said steamconnection entering the cylinder at such a point that the initialmovement of the yieldable heads will cut off the steam from the spacesbetween the liXed and the yieldable heads.

KENNEDY 'DoUGAn Witnesses:

S. SHUFELDT, K. M. IMBoDEN.

Copies oi this patent may be obtained for ive cents each, by addressingthe Commissioner of Patenta Washington, D. G.

